Current growth rates for the digital magnetic recording data storage industry show an increase in recording densities of 60 percent per year. To continue on this growth rate curve, the recording industry is being forced to make a number of significant changes in the design of the magnetic recording device. Digital magnetic recording devices for data storage generally comprise a thin film magnetic recording disk and a head or transducer which is moved along or above the surface of the rotating disk to read and write information on the disk. Advanced high areal density, thin film magnetic recording disks generally comprise preferably a textured rigid substrate, a magnetic layer such as a cobalt-based metal alloy, a protective amorphous carbon layer, and a lubricant layer such as a perfluoropolyether disposed on the carbon overcoat. The disk texture can be a full disk or, alternatively, a dual-zone texture.
The recording device comprises a positioning actuator connected to the head for moving the head to the desired location on the disk during reading or writing operations. The head is attached to a carrier or slider having an air-bearing surface which is supported during operation adjacent to the data surface of the disk by a cushion of air generated by the rotating disk. Since recording density depends exponentially on the separation distance between the recording head and the magnetic layer of the disk, lower fly heights are needed for high areal density recording. However, lower fly heights can cause an increase in the interaction of the head with the disk during normal flying. These interactions of the head and the disk result in the formation of amorphous deposits on the head and disk surfaces. These amorphous deposits result from polymerization occuring at the head-disk interface of gaseous contaminants present in the drive such as gaseous hydrocarbons, acrylates, siloxanes, and phthalates. These gaseous contaminants form from the thermal degradation of polymeric greases, adhesives, seals and lubricants present in the drive enclosure. With continued growth, these polymeric deposits can lead to a number of interface failures. For example, the formation of polymeric deposits on the magnetic recording disk can lead to an increase in the number of thermal asperities. Formation of polymeric deposits on the air bearing surface of the slider can lead to a fly height drop, accelerating the formation of these deposits. With continued growth, these deposits can cause a head crash with resulting failure of the disk drive. There is a need in the art for a disk drive which is designed to minimize the formation of thermal asperities.
It is an object of the present invention to provide an improved noncontact magnetic recording device which operates with improved resistance to polymerization of gaseous contaminants at the head-disk interface.
Other objects and advantages will be apparent from the following disclosure.